In my previous U.S. Pat. No. 3,776,203, the disclosure of all of which is herein incorporated by reference, I disclosed variable volume rotary vane pumps. During the years since my disclosure of the invention set forth in U.S. Pat. No. 3,776,203 much research and improvements have been made in rotary motion devices of the type disclosed in my previous patent. As is known in the art, the variable volume vane portions comprise a series of vanes which are located in slots, spaced around the circumference of a rotor, whose radiallly inner edges sometimes bear in contact with the bottom of the slots and whose radially external edge or head bears against the internal cylindrical surface of an outer sleeve as is described in my previous patent.
In devices of this type it is therefore necessary for the vanes to come into sealing contact with the walls of the outer sleeve while simultaneously preventing undue friction between the vanes and sleeve that would lead to wear and failure of either, or both, of these components. Because rotary devices of this type complete numerous rotations during each minute of use, it is of little wonder that the primary focus of those skilled in the art has been various attempts to promote efficient sealing contact of vanes and sleeve. Such prior art attempts employ biasing means, such as springs to assure contact of the vanes with the sleeve. However, these prior art devices are insufficient to assure adequate sealing contact, and, in the event of failure of biasing means, the devices need to be completely disassembled to replace the biasing elements.
U.S. Pat. No. 4,225,308 illustrates the use of a spring to bias the vanes radially outwardly against the internal cylindrical surface of an outer sleeve. The presence of such biasing means is insufficient to assure adequate sealing between the vanes and the internal circumference of the outer sleeve.
U.S. Pat. No. 4,222,718, although recognizing the problem of wear in a hydraulic pump or motor does not address the problem of providing adequate sealing of the vanes with the inner cylindrical wall of the outer sleeve while also preventing undue wear of the contacting surfaces.
Thus, although attempts have been made in prior art systems, for example, such as those described in the aforementioned patents, there has still been a need for a more efficient mechanism to assure effective sealing of the vanes of a rotary motor or pump with the internal cylindrical walls of an outer sleeve while simultaneously avoiding excessive wear thereof. Additionally, there is required a rotary rotor or pump of improved reliability and requiring less maintenance and repair.